In an Internet protocol (IP) network, it often needs to diagnose routes with IP packets passing through, for example, to determine whether a route for transmitting an IP packet is smooth or not as well as network equipment that the IP packet passes through. Currently, there are two route diagnosis methods in IP networks. One is packet Internet groper (ping) method, and the other is traceroute method. The two methods are briefly introduced below.
Ping Method
This method adopts an Internet control message protocol (ICMP) to echo message and response of the echo message, and is usually used in IP networks to test the reachability of network equipment. In a specific implementation, source network equipment sends an ICMP echo request packet to destination network equipment, and waits for the destination network equipment to return an ICMP echo reply packet so as to obtain a route diagnosis result according to the ICMP echo reply packet. The ICMP echo request packet carries a time stamp at which the request is sent, for calculating a round-trip time. When the ICMP echo reply packet is returned, the echo reply packet carries the time stamp at which the request is sent. The round-trip time is obtained by subtracting the time stamp carried in the echo reply packet from the current time stamp at which the packet is received. All different versions of the route diagnosis method of ping provide an −R option with a record route function.
Traceroute Method
The route diagnosis method of traceroute determines a route that an IP packet passes through from source network equipment to destination network equipment based on the principles that a source address of an ICMP response packet containing timeout information is the address of the destination network equipment. A specific implementation is described as follows. The source network equipment sends an IP packet with a time-to-live (TTL) field of 1 to the destination network equipment. First network equipment that processes the IP packet subtracts 1 from the value of the TTL field, discards the IP packet, and then sends a timeout ICMP response packet to the source network equipment. The ICMP response packet carries an IP address of the first network equipment that processes the IP packet. As such, the source network equipment obtains the IP address of the first network equipment in the route for transmitting the IP packet. After that, the source network equipment sends an IP packet with a TTL field of 2, and accordingly obtains an IP address of second network equipment in the route for transmitting the IP packet. The process is continued until the IP packet is sent to the destination network equipment, and thus IP addresses of all network equipment in the route for transmitting the IP packet are obtained. When receiving the IP packet with a TTL field of 1, the destination network equipment does not discard the IP packet, but still generates an ICMP response packet.
The two route diagnosis methods are usually employed for routine maintenance of the IP networks. By using the two route diagnosis methods, the reachability of an IP packet to the destination network equipment can be preliminarily tested, problems in the route for transmitting the IP packet can be diagnosed, and route information that the IP packet passes through can be determined. Both of the two methods adopt the IP address of the destination network equipment as a key parameter, because routes in IP networks are based on IP addresses.
The methods for diagnosing a route in an IP network are described above. Likewise, there is also a need to diagnose an application layer route in a network based on a Diameter protocol, i.e. to diagnose the reachability of the application layer route and information about Diameter nodes in the route.
FIG. 1 is a schematic view of realm-based routes in a network based on a Diameter protocol in the prior art. Referring to FIG. 1, three routes are shown (respectively indicated by fine solid lines, dashed lines, and heavy solid lines in FIG. 1, and each block represents a Diameter node). The three routes are respectively corresponding to three different applications, for example, respectively corresponding to a network access server (NAS) application of the Diameter protocol, a mobile Internet protocol (MIP) application of the Diameter protocol, and a session initiation protocol (SIP) application of the Diameter protocol. The three routes have the same destination realm, the same Diameter client A, and the same Diameter server K.
The network based on the Diameter protocol is configured by various types of Diameter nodes, including a Diameter relay, a Diameter proxy, a Diameter redirector, and a Diameter converter, in addition to the Diameter client and the Diameter server. In actual applications, each Diameter node may play different roles at the same time, for example, function as a Diameter client for one realm and as a Diameter server for another; or function as a Diameter relay for forwarding a message of one type when the message arrives and as a Diameter proxy when a message of another type arrives. As network applications based on the Diameter protocol involve different realms, different applications, and various cases such as whether the Diameter node supports a certain realm or application and whether the Diameter node passes a security authentication, the application layer routes of the network based on the Diameter protocol become quite complex. Further, different configuration policies adopted in the network and the result of capability negotiation among the Diameter nodes may also influence the conditions of the application layer routes. Therefore, there is a need to diagnose the reachability of the application layer routes and collection of topology information of the Diameter nodes in the network based on the Diameter protocol, especially in a large-scale network based on the Diameter protocol.
Currently, technical contents about attribute value pairs (AVPs) of application layer routes and application layer route information can be found in the Diameter base protocol RFC3588 and other related protocols. A specific application message carries Route-Record AVP information for loop detection of the Diameter nodes, and a Diameter server acknowledges and authorizes a route that the application message passes through. However, the inventors found in the process of implementing the present invention that the prior art fails to propose a specific diagnosis method for application layer routes, and cannot provide information for timely and effectively diagnosing the route for transmitting the application message, which is disadvantageous in finding the problem about network configuration for transmitting the application message and the problem about domain security. In addition, the AVP information also cannot provide sufficient information for route diagnosis.
Hence, there is a need for a simple and universal method for quickly and directly diagnosing an application layer route in a network based on a Diameter protocol.